content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  import java.lang.reflect.Method;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.TreeSet;
  
  /**
   * Helps generate {@link String} representations of {@link MessageLite} protos.
   */
  // TODO(dweis): Fix map fields.
  final class MessageLiteToString {
  
    private static final String LIST_SUFFIX = "List";
    private static final String BUILDER_LIST_SUFFIX = "OrBuilderList";
    private static final String BYTES_SUFFIX = "Bytes";
    
    /**
     * Returns a {@link String} representation of the {@link MessageLite} object.  The first line of
     * the {@code String} representation representation includes a comment string to uniquely identify
     * the objcet instance. This acts as an indicator that this should not be relied on for
     * comparisons.
     *
     * <p>For use by generated code only.
     */
    static String toString(MessageLite messageLite, String commentString) {
      StringBuilder buffer = new StringBuilder();
      buffer.append("# ").append(commentString);
      reflectivePrintWithIndent(messageLite, buffer, 0);
      return buffer.toString();
    }
  
    /**
     * Reflectively prints the {@link MessageLite} to the buffer at given {@code indent} level.
     *
     * @param buffer the buffer to write to
     * @param indent the number of spaces to indent the proto by
     */
    private static void reflectivePrintWithIndent(
        MessageLite messageLite, StringBuilder buffer, int indent) {
      // Build a map of method name to method. We're looking for methods like getFoo(), hasFoo(), and
      // getFooList() which might be useful for building an object's string representation.
      Map<String, Method> nameToNoArgMethod = new HashMap<String, Method>();
      Map<String, Method> nameToMethod = new HashMap<String, Method>();
      Set<String> getters = new TreeSet<String>();
      for (Method method : messageLite.getClass().getDeclaredMethods()) {
        nameToMethod.put(method.getName(), method);
        if (method.getParameterTypes().length == 0) {
          nameToNoArgMethod.put(method.getName(), method);
  
          if (method.getName().startsWith("get")) {
            getters.add(method.getName());
          }
        }
      }
  
      for (String getter : getters) {
        String suffix = getter.replaceFirst("get", "");
        if (suffix.endsWith(LIST_SUFFIX) && !suffix.endsWith(BUILDER_LIST_SUFFIX)) {
          String camelCase = suffix.substring(0, 1).toLowerCase()
              + suffix.substring(1, suffix.length() - LIST_SUFFIX.length());
          // Try to reflectively get the value and toString() the field as if it were repeated. This
          // only works if the method names have not be proguarded out or renamed.
          Method listMethod = nameToNoArgMethod.get("get" + suffix);
          if (listMethod != null && listMethod.getReturnType().equals(List.class)) {
            printField(
                buffer,
                indent,
                camelCaseToSnakeCase(camelCase),
                GeneratedMessageLite.invokeOrDie(listMethod, messageLite));
            continue;
          }
        }
  
        Method setter = nameToMethod.get("set" + suffix);
        if (setter == null) {
          continue;
        }
        if (suffix.endsWith(BYTES_SUFFIX)
            && nameToNoArgMethod.containsKey(
                "get" + suffix.substring(0, suffix.length() - "Bytes".length()))) {
          // Heuristic to skip bytes based accessors for string fields.
          continue;
        }
  
        String camelCase = suffix.substring(0, 1).toLowerCase() + suffix.substring(1);
  
        // Try to reflectively get the value and toString() the field as if it were optional. This
        // only works if the method names have not be proguarded out or renamed.
        Method getMethod = nameToNoArgMethod.get("get" + suffix);
        Method hasMethod = nameToNoArgMethod.get("has" + suffix);
        // TODO(dweis): Fix proto3 semantics.
        if (getMethod != null) {
          Object value = GeneratedMessageLite.invokeOrDie(getMethod, messageLite);
          final boolean hasValue = hasMethod == null
              ? !isDefaultValue(value)
              : (Boolean) GeneratedMessageLite.invokeOrDie(hasMethod, messageLite);
           // TODO(dweis): This doesn't stop printing oneof case twice: value and enum style.
          if (hasValue) {
            printField(
                buffer,
                indent,
                camelCaseToSnakeCase(camelCase),
                value);
          }
          continue;
        }
      }
  
      if (messageLite instanceof GeneratedMessageLite.ExtendableMessage) {
        Iterator<Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object>> iter =
            ((GeneratedMessageLite.ExtendableMessage<?, ?>) messageLite).extensions.iterator();
        while (iter.hasNext()) {
          Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object> entry = iter.next();
          printField(buffer, indent, "[" + entry.getKey().getNumber() + "]", entry.getValue());
        }
      }
  
      if (((GeneratedMessageLite<?, ?>) messageLite).unknownFields != null) {
        ((GeneratedMessageLite<?, ?>) messageLite).unknownFields.printWithIndent(buffer, indent);
      }
    }
    
    private static boolean isDefaultValue(Object o) {
      if (o instanceof Boolean) {
        return !((Boolean) o);
      }
      if (o instanceof Integer) {
        return ((Integer) o) == 0;
      }
      if (o instanceof Float) {
        return ((Float) o) == 0f;
      }
      if (o instanceof Double) {
        return ((Double) o) == 0d;
      }
      if (o instanceof String) {
        return o.equals("");
      }
      if (o instanceof ByteString) {
        return o.equals(ByteString.EMPTY);
      }
      if (o instanceof MessageLite) { // Can happen in oneofs.
        return o == ((MessageLite) o).getDefaultInstanceForType();
      }
      if (o instanceof java.lang.Enum<?>) { // Catches oneof enums.
        return ((java.lang.Enum<?>) o).ordinal() == 0;
      }
      
      return false;
    }
  
    /**
     * Formats a text proto field.
     *
     * <p>For use by generated code only.
     *
     * @param buffer the buffer to write to
     * @param indent the number of spaces the proto should be indented by
     * @param name the field name (in lower underscore case)
     * @param object the object value of the field
     */
    static final void printField(StringBuilder buffer, int indent, String name, Object object) {
      if (object instanceof List<?>) {
        List<?> list = (List<?>) object;
        for (Object entry : list) {
          printField(buffer, indent, name, entry);
        }
        return;
      }
  
      buffer.append('\n');
      for (int i = 0; i < indent; i++) {
        buffer.append(' ');
      }
      buffer.append(name);
  
      if (object instanceof String) {
        buffer.append(": \"").append(TextFormatEscaper.escapeText((String) object)).append('"');
      } else if (object instanceof ByteString) {
        buffer.append(": \"").append(TextFormatEscaper.escapeBytes((ByteString) object)).append('"');
      } else if (object instanceof GeneratedMessageLite) {
        buffer.append(" {");
        reflectivePrintWithIndent((GeneratedMessageLite<?, ?>) object, buffer, indent + 2);
        buffer.append("\n");
        for (int i = 0; i < indent; i++) {
          buffer.append(' ');
        }
        buffer.append("}");
      } else {
        buffer.append(": ").append(object.toString());
      }
    }
    
    private static final String camelCaseToSnakeCase(String camelCase) {
      StringBuilder builder = new StringBuilder();
      for (int i = 0; i < camelCase.length(); i++) {
        char ch = camelCase.charAt(i);
        if (Character.isUpperCase(ch)) {
          builder.append("_");
        }
        builder.append(Character.toLowerCase(ch));
      }
      return builder.toString();
    }
  }
  